Diameter of the extendable boom in the nose of Bismarck

[tommy303]

It is possible, but I have not seen any photograph from the operation which suggests that they were rigged and ready for use. By sticking to the middle of the passage the squadron would have kept to water too deep for mining and I would presume therefore that perhaps they did not. Maybe in the Baltic during the passage to Norway. The following might show the thin lines rigged for pulling up the otter cables:

http://www.bismarck-class.dk/bismarck/g ... ction.html

Still, the lines are so thin that they would rarely show up in most photographs and it is entirely possible they were present. Perhaps someone out there will have clearer photos than I have to work with. At any rate, during the war Royal Navy ships appear to have cables rigged going from forecastle to forefoot as a matter of routine. These are heavier and show up better, while the German ones are a thin line apparently for hauling the paravane cable out of the tube and up to the forecastle.

thomas

[Ulrich Rudofsky]

Looks plausible to me. But it seems to me a weird contraption that could not have worked well. I can't think of an instance right now were a battleship successfully evaded a mine or an aerial torpedo.

[tommy303]

Ulrich,

I personally cannot think of a time when any surface ship other than a minesweeper had been used in such a fashion. Frankly, I believe the Kriegsmarine, along with most others, depended on their minesweepers to sweep any channel a major unit would transit, at least in home waters in time of war. Since getting the system to work required a reduction in speed, it seems to me to be something of a risk either way. I suppose provisions were made, but rarely used, in case a major unit found itself without any sort of minesweeping support. It was evidently possible, but I have not come across references of it ever being done as a matter of routine, particularly since the introduction of acoustic, pressure and magnetic mines.


trf

[Groundsman]

This is an old thread but I thought I'd add what I know.

I thought that the cable from the deck through the bow tube and back up to the deck to attach to the paravane was put in place either when the ship was in dry dock or by a diver. On the Scharnhorst class there is a small hatch between the bow anchor positions where the cable entered the deck.

I know of two images that can illustrate this cable or hatch. The first is from film taken on board Gneisenau. This film is on the DVD Schlachtschiff Gneisenau Teil 1 at about 00.14 (14 seconds). It shows GU's foredeck steaming into heavy seas and if you look between the two anchors you will see sea water flushing up through the hatch. It appears to come from slightly left off centre but it is in fact off right as the film is reversed (check the run of the anchor cables). I can only guess this sea water is being forced up the Buschutz pipe. Further viewing of this film shows the derricks on both sides that would hold and lower the paravane into the sea.

Capture.JPG

(142.55 KiB) Not downloaded yet

The next picture is taken from a YouTube video of the Scharnhorst wreck:

https://www.youtube.com/watch?v=iSztbgj7pNM&t=1s

This shows a cable coming out of the Bugschutz pipe.

[Herr Nilsson]

Looks more like rusticles.

[Joe100]

I’m sure you’ve seen drawings of how this was all rigged, but one question I’ve always had, and seen dodged a dozen times, is now the line was passed from the end of bugspire to the paravane. Was it rigged by divers as I suspect?

[marcelo_malara]

I’m sure you’ve seen drawings of how this was all rigged, but one question I’ve always had, and seen dodged a dozen times, is now the line was passed from the end of bugspire to the paravane. Was it rigged by divers as I suspect?

Hi. We discussed it recently. The chains were passed before the ships sailed from port.

[Herr Nilsson]

I’m sure you’ve seen drawings of how this was all rigged, but one question I’ve always had, and seen dodged a dozen times, is now the line was passed from the end of bugspire to the paravane. Was it rigged by divers as I suspect?

That was a very complex procedure and I don't know if the following description is 100% right. There are some uncertainties are still remaining. However, to my best knowledge:
1) Through a hatch in the upperdeck a carriage on a rope was lowered inside the tube until it was hanging outside the bulbous bow.
2) The carriage was catched from the outside of the ship and pulled to the deck.
3) A rope was attached to the carriage and both were lowered to the water and pulled through the tube up to the hatch. (I think this rope was connected to itself to a kind of loop, but I'm not sure).
4) The paravane lines were attached to the rope and the lines were pulled through the tube up to the upper deck. The spire was extended either before or after pulling the lines through the tube, I don't know exactly.
5) The lines were attached to two slip stoppers to release one (or even two) in case of emergency
6) The other ends of the lines were attached to the paravane.

The rest should be the same like in other navies.

[marcelo_malara]

2) The carriage was catched from the outside of the ship and pulled to the deck.

This would be the difficult part.